example_wlan_ssid_parser.py

#/usr/bin/env python
import re
import subprocess

def get_networks_in_range_fast(lines=None):
    if lines is None:
        lines = subprocess.check_output(['nmcli', 'dev', 'wifi', 'list']).splitlines()
    re_key = re.compile(r'[A-Z]+\s*')
    first_line = lines[0]
    keylist = []
    start = 0
    while start < len(first_line):
        match = re_key.match(first_line, start)
        if match:
            end = match.end()
            keylist.append((start, end, first_line[start:end].strip().lower()))
            start = end
        else:
            # we should not end up here, but better safe than sorry
            break
    for line in lines[1:]:
        network_dict = dict(
                (key, line[start:end].strip())
                for start, end, key in keylist
            )
        # we need to remove '-signs around the ssid name
        network_dict["ssid"] = network_dict["ssid"][1:-1]
        yield network_dict

def get_networks_in_range_slow(lines=None):
    if lines is None:
        lines = subprocess.check_output(['iwlist', 'wlan0', 'scan']).splitlines()

    re_start = re.compile(r'\s+Cell\b')
    re_ssid = re.compile(r'\s+ESSID:"([^"]+)"')
    re_signal = re.compile(r'\s+Quality=(\d+)/70')
    d = None
    for line in lines:
        if re_start.match(line):
            if d:
                yield d
            d = dict(ssid='', signal='', active='')
            continue
        for regex, property_name in [
                (re_ssid, "ssid"),
                (re_signal, "signal"),
                ]:
            match = regex.match(line)
            if match:
                d[property_name] = match.groups()[0]
                break
    if d:
        yield d

test_input_fast = """\
SSID                              BSSID               MODE             FREQ       RATE       SIGNAL   SECURITY   ACTIVE  
'UPC1859162'                      XX:XX:XX:XX:XX:XX   Infrastructure   2412 MHz   54 MB/s    67       WPA WPA2   yes     
'dlink'                           XX:XX:XX:XX:XX:XX   Infrastructure   2412 MHz   54 MB/s    24       WPA WPA2   no      
""".splitlines()

test_input_slow = """\
wlan0     Scan completed :
          Cell 01 - Address: XX:XX:XX:XX:XX:XX
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=60/70  Signal level=-50 dBm  
                    Encryption key:on
                    ESSID:"UPC1859162"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                              24 Mb/s; 36 Mb/s; 54 Mb/s
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s
                    Mode:Master
                Extra:tsf=XXXXXXXXXXXXXXXX
                    Extra: Last beacon: 16ms ago
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : CCMP TKIP
                        Authentication Suites (1) : PSK
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: WPA Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : CCMP TKIP
                        Authentication Suites (1) : PSK
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
          Cell 02 - Address: XX:XX:XX:XX:XX:XX
                    Channel:1
                    Frequency:2.412 GHz (Channel 1)
                    Quality=30/70  Signal level=-50 dBm  
                    Encryption key:on
                    ESSID:"TestNetwork"
                    Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 18 Mb/s
                              24 Mb/s; 36 Mb/s; 54 Mb/s
                    Bit Rates:6 Mb/s; 9 Mb/s; 12 Mb/s; 48 Mb/s
                    Mode:Master
                Extra:tsf=XXXXXXXXXXXXXXXX
                    Extra: Last beacon: 16ms ago
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: IEEE 802.11i/WPA2 Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : CCMP TKIP
                        Authentication Suites (1) : PSK
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: WPA Version 1
                        Group Cipher : TKIP
                        Pairwise Ciphers (2) : CCMP TKIP
                        Authentication Suites (1) : PSK
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                    IE: Unknown: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

""".splitlines()

if __name__ == "__main__":
    from pprint import pprint
    fast_list = list(get_networks_in_range_fast(test_input_fast))
    slow_list = list(get_networks_in_range_slow(test_input_slow))

    assert len(fast_list) == 2
    assert len(slow_list) == 2

    # test fast parser
    assert fast_list[0]["active"] == "yes"
    assert fast_list[1]["active"] == "no"

    assert fast_list[0]["ssid"] == "UPC1859162"
    assert fast_list[1]["ssid"] == "dlink"

    assert fast_list[0]["signal"] == "67"
    assert fast_list[1]["signal"] == "24"

    # test slow parser
    assert slow_list[0]["active"] == ""
    assert slow_list[1]["active"] == ""

    assert slow_list[0]["ssid"] == "UPC1859162"
    assert slow_list[1]["ssid"] == "TestNetwork"

    assert slow_list[0]["signal"] == "60"
    assert slow_list[1]["signal"] == "30"

    print("tests done")